Frontotemporal Dementia Group Research Articles

Distinct Cognitive Trajectories According to Amyloid Positivity in Non-Alzheimer Disease Dementias.

The clinical effects of β-amyloid positivity (Aβ+) on copathologies in various dementias remain relatively underexamined. Thus, the present study was conducted to investigate the prevalence and clinical effects of Aβ+ in subcortical vascular cognitive impairment (SVCI) and frontotemporal dementia (FTD). We enrolled SVCI (n = 583), FTD (n = 152), and cognitively unimpaired (CU) participants (n = 1,249) who underwent Aβ PET scans. The odds of having Aβ+ were subsequently compared among the diagnostic groups (CU, SVCI, and FTD) according to age and apolipoprotein E genotype. Additionally, a linear mixed-effects model was used to investigate the effects of Aβ+ on cognitive trajectories in SVCI and FTD. Compared with CU, the SVCI group had a higher prevalence of Aβ+ in the 75 to 90 years age group (adjusted odds ratio, 1.97; 95% confidence interval, 1.36-2.85; P < 0.001), as well as within the apolipoprotein E ε3/ε3 group (adjusted odds ratio, 1.78; 95% confidence interval, 1.20-2.63; P = 0.001), whereas the FTD group showed no difference in Aβ+ prevalence. Aβ+ was associated with a worse cognitive trajectory in SVCI (adjusted β-coefficient = -0.6424; P < 0.001), but not in FTD. These findings contribute to our understanding of Aβ biomarker traits in various dementias in Korea.

Automated Volumetric Software in Dementia: Help or Hindrance to the Neuroradiologist?

Brain atrophy occurs in the late stage of dementia, yet structural MRI is widely used in the work-up. Atrophy patterns can suggest a diagnosis of Alzheimer disease (AD) or frontotemporal dementia (FTD) but are difficult to assess visually. We hypothesized that the availability of a quantitative volumetric brain MRI report would increase neuroradiologists' accuracy in diagnosing AD, FTD, or healthy controls compared with visual assessment. Twenty-two patients with AD, 17 with FTD, and 21 cognitively healthy patients were identified from the electronic health systems record and a behavioral neurology clinic. Four neuroradiologists evaluated T1-weighted anatomic MRI studies with and without a volumetric report. Outcome measures were the proportion of correct diagnoses of neurodegenerative disease versus normal aging ("rough accuracy") and AD versus FTD ("exact accuracy"). Generalized linear mixed models were fit to assess whether the use of a volumetric report was associated with higher accuracy, accounting for random effects of within-rater and within-subject variability. Post hoc within-group analysis was performed with multiple comparisons correction. Residualized volumes were tested for an association with the diagnosis using ANOVA. There was no statistically significant effect of the report on overall correct diagnoses. The proportion of "exact" correct diagnoses was higher with the report versus without the report for AD (0.52 versus 0.38) and FTD (0.49 versus 0.32) and lower for cognitively healthy (0.75 versus 0.89). The proportion of "rough" correct diagnoses of neurodegenerative disease was higher with the report than without the report within the AD group (0.59 versus 0.41), and it was similar within the FTD group (0.66 versus 0.63). Post hoc within-group analysis suggested that the report increased the accuracy in AD (OR = 2.77) and decreased the accuracy in cognitively healthy (OR = 0.25). Residualized hippocampal volumes were smaller in AD (mean difference -1.8; multiple comparisons correction, -2.8 to -0.8; P < .001) and FTD (mean difference -1.2; multiple comparisons correction, -2.2 to -0.1; P = .02) compared with cognitively healthy. The availability of a brain volumetric report did not improve neuroradiologists' accuracy over visual assessment in diagnosing AD or FTD in this limited sample. Post hoc analysis suggested that the report may have biased readers incorrectly toward a diagnosis of neurodegeneration in cognitively healthy adults.

MiR-92a-3p and miR-320a are Upregulated in Plasma Neuron-Derived Extracellular Vesicles of Patients with Frontotemporal Dementia.

Despite the efforts to identify fluid biomarkers to improve diagnosis of Frontotemporal dementia (FTD), only a few candidates have been described in recent years. In a previous study, we identified three circulating miRNAs (miR-92a-3p, miR-320a and miR-320b) differentially expressed in FTD patients with respect to healthy controls and/or Alzheimer's disease (AD) patients. Now, we investigated whether those changes could be due to miRNAs contained in neuron-derived extracellular vesicles (NDEVs). We also evaluated miRNAs content in total plasma EVs and in CSF samples. The analysis of plasma NDEVs carried out on 40 subjects including controls (n = 13), FTD (n = 13) and AD (n = 14) patients, showed that both miR-92a-3p and miR-320a levels were triplicated in the FTD group if compared with CT and AD patients. Increased levels of the same miRNAs were found also in CSF derived from FTD group compared to CTs. No differences were observed in expression levels of miR-320b among the three groups. Worthy of note, all miRNAs analysed were increased in an FTD cell model, MAPT IVS10 + 16 neurons. Our results suggest that miR-92a and miR-320a in NDEVs could be proposed as FTD biomarkers.

Distribution of neuropsychiatric profiles and comorbid diseases in dementia subtypes

Objectives: Alzheimer’s disease (AH) is the most prevalent cause of dementia, followed closely by vascular dementia. Mixed vascular-Alzheimer’s dementia (MVAD) is more evident in individuals aged 80 and above. Frontotemporal dementia (FTD) is the second most common cause of early-onset dementia after AH. Vascular risk factors play important role in the pathogenesis of dementia syndromes. Behavioral and psychological symptoms represent a significant portion of the non-cognitive manifestations in dementia patients. This study aimed to evaluate the distribution of chronic diseases, behavioral disorders, psychiatric findings, and medication use in patients followed with different dementia diagnoses. Methods: Prevalance of chronic diseases, behavioral disorders, psychiatric findings as well as the usage of antidepressant and antipsychotic medications among patients followed up in dementia outpatient clinics with the diagnosis of AD, mild cognitive impairment (MCI), vascular dementia (VaD), FTD, and MVAD were investigated. Neuropsychiatric inventory (NPI) was applied to the patients. Results: Four hundred and fifty-five patients were accepted in the study. The patients were distributed as follows: AD (n=303, female/male: 187/115, age = 78±8 years), MCI (n=53, female/male: 31/22, age = 69±10 years), VaD (n=31, female/male: 18/13, age = 68±9 years), FTD (n=32, female/male: 17/15, age = 68±9 years), and MVAD (n=36, female/male: 16/20, age = 76±10 years). Both AD and MVAD groups were significantly older than the other groups (F = 23.2, P&amp;lt;0.0001). The ratio of comorbid chronic diseases was 80% in the AD group, 72% in the MCI group, 91% in the VaD group, 59% in the FTD group, and 93% in the MVAD group. In the whole group, antipsychotic drug use was 27.5% and antidepressant drug use was 28.9%. The mean NPI score was 32.9±28 in antipsychotic users and 16±19 in non-users (P&amp;lt;0.0001). The mean NPI of antidepressant users was 17.6±19 and 21.9±25 (P=0.055) in non-users. Conclusion: There is a comorbid chronic disease burden in all dementia subtypes, although at varying intensities, and as the chronic disease burden increases, behavioral disorders and psychotic findings increase, and accordingly, the use of antipsychotics also increases.

Analysis of the alpha activity envelope in electroencephalography in relation to the ratio of excitatory to inhibitory neural activity.

Alpha waves, one of the major components of resting and awake cortical activity in human electroencephalography (EEG), are known to show waxing and waning, but this phenomenon has rarely been analyzed. In the present study, we analyzed this phenomenon from the viewpoint of excitation and inhibition. The alpha wave envelope was subjected to secondary differentiation. This gave the positive (acceleration positive, Ap) and negative (acceleration negative, An) values of acceleration and their ratio (Ap-An ratio) at each sampling point of the envelope signals for 60 seconds. This analysis was performed on 36 participants with Alzheimer's disease (AD), 23 with frontotemporal dementia (FTD) and 29 age-matched healthy participants (NC) whose data were provided as open datasets. The mean values of the Ap-An ratio for 60 seconds at each EEG electrode were compared between the NC and AD/FTD groups. The AD (1.41 ±0.01 (SD)) and FTD (1.40 ±0.02) groups showed a larger Ap-An ratio than the NC group (1.38 ±0.02, p<0.05). A significant correlation between the envelope amplitude of alpha activity and the Ap-An ratio was observed at most electrodes in the NC group (Pearson's correlation coefficient, r = -0.92 ±0.15, mean for all electrodes), whereas the correlation was disrupted in AD (-0.09 ±0.21, p<0.05) and disrupted in the frontal region in the FTD group. The present method analyzed the envelope of alpha waves from a new perspective, that of excitation and inhibition, and it could detect properties of the EEG, Ap-An ratio, that have not been revealed by existing methods. The present study proposed a new method to analyze the alpha activity envelope in electroencephalography, which could be related to excitatory and inhibitory neural activity.

Cognitive trajectories preluding the onset of different dementia entities: a descriptive longitudinal study using the NACC database

ObjectiveTo describe the 10-year preclinical cognitive trajectories of older, non-demented individuals towards the onset of the four most prevalent types of dementia, i.e., Alzheimer’s disease(AD), Lewy body(LBD), vascular(VD) and frontotemporal dementia(FTD).MethodsOur analysis focused on data from older (≥ 60years) NACC (National Alzheimer’s Coordinating Center) participants. Four distinct presymptomatic dementia groups (AD-LBD-VD-FTD) and a comparison group of cognitively unimpaired(CU) participants were formed. Comprehensive cognitive assessments involving verbal episodic memory, semantic verbal fluency, confrontation naming, mental processing speed – attention and executive function – cognitive flexibility were conducted at baseline and on an approximately yearly basis. Descriptive analyses (adjusted general linear models) were performed to determine and compare the yearly cognitive scores of each group throughout the follow-up. Exploratory analyses were conducted to estimate the rates of cognitive decline.ResultsThere were 3343 participants who developed AD, 247 LBD, 108 FTD, 155 VD and 3398 composed the CU group. Participants with AD performed worse on episodic memory than those with VD and LBD for about 3 to 4 years prior to dementia onset (the FTD group documented an intermediate course). Presymptomatic verbal fluency and confrontation naming trajectories differentiated quite well between the FTD group and the remaining dementia entities. Participants with incident LBD and VD performed worse than those with AD on executive functions and mental processing speed-attention since about 5 years prior to the onset of dementia, and worse than those with FTD more proximally to the diagnosis of the disorder.ConclusionsHeterogeneous cognitive trajectories characterize the presymptomatic courses of the most prevalent dementia entities.

Identifying clinical phenotypes of frontotemporal dementia in post-9/11 era veterans using natural language processing.

Frontotemporal dementia (FTD) encompasses a clinically and pathologically diverse group of neurodegenerative disorders, yet little work has quantified the unique phenotypic clinical presentations of FTD among post-9/11 era veterans. To identify phenotypes of FTD using natural language processing (NLP) aided medical chart reviews of post-9/11 era U.S. military Veterans diagnosed with FTD in Veterans Health Administration care. A medical record chart review of clinician/provider notes was conducted using a Natural Language Processing (NLP) tool, which extracted features related to cognitive dysfunction. NLP features were further organized into seven Research Domain Criteria Initiative (RDoC) domains, which were clustered to identify distinct phenotypes. Veterans with FTD were more likely to have notes that reflected the RDoC domains, with cognitive and positive valence domains showing the greatest difference across groups. Clustering of domains identified three symptom phenotypes agnostic to time of an individual having FTD, categorized as Low (16.4%), Moderate (69.2%), and High (14.5%) distress. Comparison across distress groups showed significant differences in physical and psychological characteristics, particularly prior history of head injury, insomnia, cardiac issues, anxiety, and alcohol misuse. The clustering result within the FTD group demonstrated a phenotype variant that exhibited a combination of language and behavioral symptoms. This phenotype presented with manifestations indicative of both language-related impairments and behavioral changes, showcasing the coexistence of features from both domains within the same individual. This study suggests FTD also presents across a continuum of severity and symptom distress, both within and across variants. The intensity of distress evident in clinical notes tends to cluster with more co-occurring conditions. This examination of phenotypic heterogeneity in clinical notes indicates that sensitivity to FTD diagnosis may be correlated to overall symptom distress, and future work incorporating NLP and phenotyping may help promote strategies for early detection of FTD.

Plasma Neurofilament Light Chain predicts neuroimaging alterations and functional decline in frontotemporal dementia

AbstractBackgroundPlasma Neurofilament light chain (pNfL) is a promising biomarker to discriminate Frontotemporal dementia (FTD) from other diagnoses such as Alzheimer’s disease (AD) or psychiatric disorders. Currently, the diagnostic criteria for FTD syndromes are structured hierarchically into “Possible”, “Probable” and “Definite” levels depending on the degree of confidence set by biomarkers. We aim to study the diagnostic and prognostic values of pNfL in the different confidence levels of FTD diagnosis.MethodPatients fulfilling criteria for FTD were classified as “Possible”, “Probable” or “Definite” FTD based on the current diagnostic criteria. pNfL levels were determined with SiMoA, and then compared to Control and AD groups, as well as within the different levels of confidence in the FTD diagnosis.Result187 subjects were included: 37 controls, 79 AD and 71 FTD (11 Possible, 49 Probable and 11 Definite). The FTD group showed higher concentrations of pNfL than the Control (p &lt; 0.001, AUC: 0.817) and the AD groups (p &lt; 0.001, AUC: 0.677) (Figure 1A and 1B).Within the FTD group, pNfL levels differed across the different diagnostic confidence levels (Figure 1C). Subjects with Probable and Definite FTD showed higher levels of pNfL than subjects with Possible FTD (p &lt; 0.001 and p &lt; 0.01 respectively). By contrast, the Possible FTD group did not show differences in pNfL concentrations with the control group. In that sense, the diagnostic value of pNfL varied according to the different grades of diagnostic confidence (Figure 1D), with cases with probable or definite FTD exhibiting an excellent AUC to distinguish from controls (AUC 0.860 and 0.908 respectively), but with no discrimination between possible FTD and controls (AUC 0.583).pNfL presented an excellent performance in the differentiation of structural or functional impairment in the neuroimage (AUC 0.94, and AUC 0.86 respectively) (Figure 2). Finally, higher baseline pNfL levels were associated with worse clinical progression in FTD cases (Figure 3).ConclusionpNfL were higher in FTD patients compared to controls or AD patients. However, we found significant variation across the different confidence levels of FTD diagnosis. Finally, pNfL predicted neuroimage alterations and a worse clinical progression in FTD patients.

Statistical analysis to identify MRI markers for Alzheimer’s Disease: why moving towards AI?

AbstractBackgroundAlzheimer’s disease (AD) is characterized by progressive neurodegeneration of some brain structures and cognitive function decline. To evaluate the anatomical changes, structural Magnetic Resonance Imaging (sMRI) is a non‐invasive examination and allows the quantification of brain atrophy. Some of the affected structures could be common with other dementia types such as frontotemporal dementia (FTD) and dementia with Lewy bodies (DLB). The objective of this work is to identify specific affected structures in patients with AD to healthy individuals, and to patients suffering from FTD and DLB. This is a part of a larger effort to develop methods to better diagnose AD and to find specific markers of this dementia type.MethodThe ADDIA clinical study (EU‐H2020 project led by Firalis company) enrolled 800 participants and was designed to obtain high‐quality samples for the discovery of novel biomarkers for early and differential diagnosis of AD. The sMRI of 623 participants with the above‐mentioned pathologies and healthy individuals were analyzed and the volume of different areas measured with the software FreeSurfer. Statistics were performed to define significant differences in brain volumes between groups.ResultOne hundred and twelve brain areas were analyzed for volume by study participant. Compared with a healthy population, the atrophy of structures observed in AD patients almost completely overlaps with the one observed in DLB and FTD patients. When the DLB and FTD groups are compared to a healthy population, one brain area is specific in DLB patients and fifty‐eight in FTD patients. However, on these fifty‐eight affected brain areas, forty‐seven overlap with the mild AD patient group.ConclusionThe measurement from imaging modality is not enough precise to report biomarkers as affected areas specific to the type of dementia. However, a promising framework lies in the application of machine and deep learning algorithms on a set of modalities: imaging, clinical and omics. These new tools allow for a finer understanding of data and a personalized approach to diagnosis. In preparation for this multimodal integration framework, the above categories of algorithms will be applied on MRI images. This will permit to discriminate AD from other dementia types at the individual level.

Vascular dysfunction in behavior‐variant frontotemporal dementia

AbstractBackgroundThe vascular disturbance was recently found in a postmortem study of frontotemporal dementia (FTD), but whether vascular dysfunction exists in the early stage of FTD remains elusive. The study aimed to explore whether there was evidence of vascular dysfunction in FTD and its relationship with central neurodegeneration and the clinical outcome.MethodTwenty patients with behavior frontotemporal dementia (bvFTD) were enrolled and underwent assessment of peripheral plasma vascular markers, positron emission tomography/magnetic resonance imaging, and neuropsychological examinations. Group difference was tested using the student’s t‐test and Mann‐Whitney U test. Partial correlation analysis was implemented using age and sex as covariates to explore the association between peripheral vascular markers, neuroimaging, and clinical measures.ResultAll four factors including matrix metalloproteinases‐1(MMP‐1), matrix metalloproteinases‐3 (MMP‐3), Osteopontin, and pentraxin‐3 are increased in the FTD group. The plasma level of MMP‐1 was negatively correlated with the gray matter metabolism of the prefrontal cortex (r = ‐0.5119, p = 0.0210) and the anterior cingulate cortex (r = ‐0.4685, p = 0.0269). MMP‐3 was negatively correlated with the gray matter metabolism of the anterior temporal cortex (r = ‐0.4650, p = 0.0388). Pentraxin‐3 was negatively correlated with age at sampling (r = ‐0.5024, p = 0.0240) and age at onset (r = ‐0.5693, p = 0.0088). No other significant associations were found in other vascular cytokines and clinical measures.ConclusionThe vascular disturbance was found in patients with bvFTD and associated with the disease‐specific neurodegeneration pattern, indicating vascular dysfunction and perturbance of the BBB participation in the pathogenesis of FTD. The vascular pathway might be a promising target for future potential therapy.

Hearing symptom profiles in Alzheimer’s disease and frontotemporal dementia

AbstractBackgroundHearing loss has emerged as a marker of cognitive decline and potential treatment target in dementia, however the symptom profiles that characterise hearing impairment in different dementia syndromes are poorly characterised. Beyond sound detection, these diseases impair aspects of auditory perception that are crucial for communication in daily life. Here we addressed changes in everyday hearing function in Alzheimer’s disease and frontotemporal dementia syndromes, using standardised auditory symptom questionnaires completed by patients’ caregivers.MethodPrimary caregivers for patients with Alzheimer’s disease (n = 20), logopenic variant primary progressive aphasia (n = 8), nonfluent variant primary progressive aphasia (n = 13), semantic variant primary progressive aphasia (n = 13) and behavioural variant frontotemporal dementia (n = 18) completed the Hearing Impairment Impact – Significant Other Profile, adapted Amsterdam Inventory for Auditory Disability and Khalfa Hyperacusis questionnaires. The Amsterdam Inventory for Auditory Disability was also completed by 15 healthy age‐matched individuals. No participant had a past history of significant otological disease.ResultScores on the Hearing Impairment Impact – Significant Other Profile and Khalfa Hyperacusis Questionnaire respectively demonstrated greater carer burden and increased sensitivity to sound in the behavioural variant frontotemporal dementia group compared with the Alzheimer’s disease group. On the Amsterdam Inventory for Auditory Disability, multi‐domain hearing difficulties were endorsed for the behavioural variant frontotemporal dementia and primary progressive aphasia groups relative to healthy controls, and total scores in the logopenic and semantic variant primary progressive aphasia groups were significantly worse than both the healthy control and Alzheimer’s disease groups. Syndromic groups showed differentiable hearing profiles across hearing domains.ConclusionMajor dementia syndromes have distinct profiles of everyday hearing difficulty, and patients with frontotemporal dementia and progressive aphasia syndromes may have particularly marked (albeit often unrecognised) changes in their hearing. These findings should motivate the development of bespoke auditory tests to assess central hearing function and personalised hearing management strategies in these diseases.

Establishing the link between motivational disturbances and behavioural rigidity in frontotemporal dementia.

Rigid and inflexible behaviours are common in frontotemporal dementia (FTD), manifesting in compulsive pursuit of specific interests, routines, and rituals. Paradoxically, these changes occur alongside profound motivational disturbances including apathy and anhedonia. While posited to be related, no study to date has explored the link between motivational changes and behavioural rigidity in FTD. Carer ratings for 71 FTD participants (26 semantic dementia [SD], 45 behavioural variant [bvFTD]) were obtained on the Dimensional Apathy Scale (apathy), the Snaith-Hamilton Pleasure Scale (hedonic tone) and the Cambridge Behavioural Inventory-Revised (CBI-R; behavioural changes). A rigidity index was created from existing items on the CBI-R. Whole-brain voxel-based morphometry was used to explore associations between rigidity and grey matter intensity in the combined FTD group. Behavioural rigidity was significantly related to apathy severity (r = 0.57) and decreased hedonic tone (r = -0.36) in the combined FTD group. Multiple linear regression revealed a significant diagnosis × hedonic tone interaction (β = -1.40), whereby lower hedonic tone predicted rigidity in SD (r = -0.65) but not in bvFTD (r = -0.18). In contrast, the relationship between rigidity and apathy did not differ between the groups (β = -0.42). At the neural level, rigidity correlated with degeneration of predominantly right-sided frontostriatal structures including, notably, the nucleus accumbens. As the first study to demonstrate a link between motivational changes and behavioural rigidity in FTD, our findings have important clinical implications. By identifying candidate mechanisms of behavioural rigidity, our findings can inform targeted interventions to manage inflexible patterns of thought and behaviour in daily life.

Does cognitive decline influence signing?

ObjectiveThe study explored the change in handwritten signature in neurodegenerative diseases by using of a rater-based approach.MethodsFour independent observers were required to compare a pair of signatures (on average, 5 years elapsed between the two signatures) made by 103 patients (mean age 72 years) with Alzheimer’s disease (AD) or frontotemporal dementia (FTD) and by 31 healthy participants (HC; mean age 73 years), judging their change according to a 0–1 rating scale (0 = similar or 1 = different). If a signature change was detected, the rater had also to report which signature features (spatial layout, omitted/added/switched letters or names, shape of letter, pen-flow) changed on the same 0–1 scale. For the AD and FTD groups, one signature was collected prior to the diagnosis of dementia, the other subsequent.ResultsA signature change was reported by raters in 36% of AD patients, 44% of FTD, and 17% of HC, with significant differences between both clinical groups and HC (vs. AD, p = .01; vs. FTD, p = .001). There was not a distinctive marker of the signature change (i.e., feature change) in patients with dementia. Moreover, the signature changes in neurological patients were unrelated to their clinical and demographic characteristics (age, sex, education, time elapsed between the two signatures, Mini-mental State Examination score).ConclusionThe findings suggest a resistance of handwritten signature in neurodegenerative diseases and in physiological aging, also suggesting that the signature may be an unreliable indicator of the cognitive status in AD and FTD, at least if subjectively evaluated.

Cerebrospinal fluid neurofilament light chain and total-tau as biomarkers of neurodegeneration in Alzheimer's disease and frontotemporal dementia

IntroductionCSF Neurofilament light chain(NfL) is a promising biomarker of neurodegeneration, but its utility in discriminating between Alzheimer's disease(AD) and frontotemporal dementia(FTD) is limited. Methods105 patients with clinical-biological diagnosis of mild cognitive impairment(MCI) due to AD (N = 72) or clinical diagnosis of FTD (N = 33) underwent neuropsychological assessment and CSF Aβ42/40, p-tau181, total-tau and NfL quantification. Group comparisons, correlations between continuous variables and ROC curve analysis were carried out to assess NfL role in discriminating between MCI due to AD and FTD, exploring the associations between NfL, ATN biomarkers and neuropsychological measures. ResultsNfL levels were significantly lower in the AD group, while levels of total-tau were higher. In the FTD group, significant correlations were found between NfL, p-tau181 and total-tau, and between NfL and cognitive performances. In the AD group, NfL levels were directly correlated with total-tau and p-tau181; Aβ42/40 ratio was inversely correlated with total-tau and p-tau181, but not with NfL. Moreover, p-tau181 and t-tau levels were found to be associated with episodic memory and lexical-semantic impairment. Total-tau/NfL ratio differentiated prodromal-AD from FTD with an AUC of 0.951, higher than the individual measures. Discussion & conclusionsThe results support that NfL and total-tau levels reflect distinct pathophysiological neurodegeneration mechanisms, independent and dependent of Aβ pathology, respectively, Combining them may enhance both markers reliability, their ratio showing high accuracy in distinguishing MCI due to AD from FTD. Moreover, our results revealed associations between NfL and disease severity in FTD and between tauopathy and episodic memory and lexical-semantic impairment in prodromal-AD.

Urine as matrix for analysis of neurofilament light chain is not suitable to distinguish frontotemporal dementia from psychiatric diseases.

The clinical overlap of frontotemporal dementia and primary psychiatric diseases hampers diagnostic distinction, leading to frequent misdiagnosis and diagnostic delay. Neurofilament light chain has shown great potential in CSF and blood for the distinction of frontotemporal dementia from primary psychiatric diseases. Measurement of neurofilament light chain in urine would be even more patient-friendly. We aimed to test the performance of neurofilament light chain urine measurements for diagnostics in frontotemporal dementia and to assess their correlation with serum levels. Fifty-five subjects (n = 19 frontotemporal dementia, n = 19 primary psychiatric diseases and n = 17 controls) were included with available paired urine and serum samples. All subjects underwent standardized extensive diagnostic assessment. Samples were analysed with the ultrasensitive single molecule array neurofilament light chain assay. Neurofilament light chain group comparisons were performed adjusted for age, sex and geriatric depression scale. In the majority of the cohort, neurofilament light chain concentrations were not detectable in urine (n = 6 samples above lower limit of detection (0.038 pg/ml): n = 5 frontotemporal dementia, n = 1 primary psychiatric disease). The frequency of a detectable neurofilament light chain level in urine in the frontotemporal dementia group did not differ from psychiatric disorders (Fisher Exact-test P = 0.180). In the individuals with detectable urine neurofilament light chain values, there was no correlation between the urine and serum neurofilament light chain levels. As expected, serum neurofilament light chain levels were higher in frontotemporal dementia compared to primary psychiatric diseases and controls (P < 0.001), adjusted for age, sex and geriatric depression scale. Receiver operating characteristic curve analysis of serum neurofilament light chain of frontotemporal dementia versus primary psychiatric diseases showed an area under the curve of 0.978 95% confidence interval 0.941-1.000, P < 0.001. Urine is not suitable as a matrix for neurofilament light chain analysis and serum neurofilament light chain is still the most patient-friendly matrix for differentiation between frontotemporal dementia and primary psychiatric diseases.

Neuropsychiatric Symptom Burden across Neurodegenerative Disorders and its Association with Function.

Neuropsychiatric symptoms (NPS) are prevalent in neurodegenerative disorders, however, their frequency and impact on function across different disorders is not well understood. We compared the frequency and severity of NPS across Alzheimer's disease (AD) (either with mild cognitive impairment or dementia), Cerebrovascular disease (CVD), Parkinson's disease (PD), frontotemporal dementia (FTD), and amyotrophic lateral sclerosis (ALS), and explored the association between NPS burden and function. We obtained data from Ontario Neurodegenerative Disease Research Initiative (ONDRI) that included following cohorts: AD (N = 111), CVD (N = 148), PD (N = 136), FTD (N = 50) and ALS (N = 36). We compared the frequency and severity of individual NPS (assessed by the neuropsychiatric inventory questionnaire) across cohorts using generalized estimating equations and analysis of variance. Second, we assessed the relationship of NPS burden with instrumental (iADLs) and basic (ADLs) activities of living across cohorts using multivariate linear regression while adjusting for relevant demographic and clinical covariates. Frequency of NPS varied across cohorts (χ2(4) = 34.4, p < .001), with post-hoc tests showing that FTD had the greatest frequency as compared to all other cohorts. The FTD cohort also had the greatest severity of NPS (H(4) = 34.5, p < .001). Further, there were differences among cohorts in terms of the association between NPS burden and ADLs (F(4,461) = 3.1, p = 0.02). Post-hoc comparisons suggested that this finding was driven by the FTD group, however, the differences did not remain significant following Bonferroni correction. There were no differences among cohorts in terms of the association between NPS burden and IADLs. NPS frequency and severity are markedly greater in FTD as compared to other neurodegenerative diseases. Further, NPS burden appears to be associated differently with function across neurodegenerative disorders, highlighting the need for individualized clinical interventions.

Traumatic Brain Injury Associates with an Earlier Onset in Sporadic Frontotemporal Dementia.

Currently, there are few studies considering possible modifiable risk factors of frontotemporal dementia (FTD). In this retrospective case-control study, we evaluated whether a history of traumatic brain injury (TBI) associates with a diagnosis of FTD or modulates the clinical phenotype or onset age in FTD patients. We compared the prevalence of prior TBI between individuals with FTD (N = 218) and age and sex-matched AD patients (N = 214) or healthy controls (HC; N = 100). Based on the patient records, an individual was categorized to the TBI+ group if they were reported to have suffered from TBI during lifetime. The possible associations of TBI with age of onset and disease duration were also evaluated in the whole FTD patient group or separately in the sporadic and genetic FTD groups. The prevalence of previous TBI was the highest in the FTD group (19.3%) when compared to the AD group (13.1%, p = 0.050) or HC group (12%, p = 0.108, not significant). Preceding TBI was more often associated with the sporadic FTD cases than the C9orf72 repeat expansion-carrying FTD cases (p = 0.003). Furthermore, comparison of the TBI+ and TBI- FTD groups indicated that previous TBI was associated with an earlier onset age in the FTD patients (B = 3.066, p = 0.010). A preceding TBI associates especially with sporadic FTD and with earlier onset of symptoms. The results of this study suggest that TBI may be a triggering factor for the neurodegenerative processes in FTD. However, understanding the precise underlying mechanisms still needs further studies.

Application of Clock Drawing Test in Evaluating Different Types of Dementias (Alzheimer’s Disease, Vascular Dementia and Fronto-temporal Dementia): A Cross-sectional Observational Study

Introduction: The Clock Drawing Test (CDT) is a highly effective screening tool for assessing cognitive function. It complements the Mental State Examination (MSE) in the early detection of various types of dementia and the evaluation of cognitive functions. Documenting the specific type of error in clock drawing significantly enhances the clinical evaluation of dementia patients in an economical manner. The CDT can effectively detect errors in execution and visuospatial functions associated with different types of dementia, including Alzheimer’s Disease (AD), Vascular Dementia (VD), and Frontotemporal Dementia (FTD). Additionally, it allows for a comparative analysis of the CDT with the severity of dementia assessed by the Bengal Mental Status Examination (BMSE) Scale. Aim: Present study aims to determine the ability of the CDT to scriminate these three disorders AD, VD, and FTD by analysing patterns of error in clock drawing. Materials and Methods: This cross-sectional observational study was conducted at the Department of Neuromedicine, Memory Clinic, Medical College, Kolkata, West Bengal, India, from March 2019 to February 2020. The diagnosis of dementia was made based on the Diagnostic and Statistical Manual of Mental Disorders- Fifth Edition (DSM-V) criteria for AD and VD, and the Rascovsky Criteria for FTD. A total of 80 patients were included in the study, with 40 in the AD group, 30 in the VD group, and 10 in the FTD group, considering 80% power and a 5% probability of error. Dementia severity was assessed using the BMSE [Annexure-III]. The subjects were provided with an 8.5×11-inch blank sheet of paper and a pencil, and were asked to draw a clock, including all the numbers, and set the hands to 10 minutes past 11. They were also requested to copy a clock as accurately as possible from a model. The resulting drawings were then analysed quantitatively by revised scale score and qualitatively using Rouleau’s qualitative analysis of clock drawing. Numerical variables were compared between groups using the Analysis of Variance (ANOVA) test and the Wilcoxon test, depending on the distribution’s normalcy. All analyses were two-tailed, and p&lt;0.05 was considered statistically significant. Results: When comparing the revised quantitative scale, the CDT score showed a significant difference between the three groups (AD, VD, and FTD) with mean scores of 2.91, 2.9, and 0.7, respectively (p=0.01). The size of the drawn clocks also showed a significant difference (p=0.006) among the AD, VD, and FTD groups, with sizes of 21.27, 18.63, and 16.7, respectively. The BMSE score also showed a significant difference between AD and FTD (p&lt;0.05), as well as between AD and VD (p&lt;0.05). Clock size was significantly different between AD and VD (p&lt;0.05). There were no significant differences observed regarding graphical difficulty, stimulus-bound response, conceptual deficits, spatial and/or planning deficits, and perseveration among the three groups. Conclusion: Qualitative analysis of the CDT contributes to the identification of different types of dementia by enabling the description of specific errors. A significant inter-group difference was found in the BMSE score, but it could not pinpoint the domains of cognitive deficits, whereas the CDT can detect those.

Shorter disease duration in females with sporadic frontotemporal dementia

AbstractBackgroundPrevious reported sex differences on disease duration (DD) of frontotemporal dementia (FTD) have been inconsistent and lack the comparison between genetic and sporadic FTD. Our aim was to study the difference in disease duration between males and females in genetic and sporadic FTD.MethodMortality data was obtained from 61 deceased patients with genetic FTD (52% male) and 117 deceased patients with sporadic FTD (64% male) from the international FTD cohort previously reported by de Boer et al., 2021. The age at symptom onset (AAO), age at death (AAD) and the DD (defined as the time between age at symptom onset and age at death) were compared between males and females in the genetic and sporadic FTD group using Mann Whitney U tests.ResultGenetic FTD did not show significant sex differences in AAO, AAD and DD (p = 0.3, p = 0.3, p = 0.8 respectively, Figure 1). In sporadic FTD, the AAO and AAD did not significantly differ between males and females (p = 0.8 and p = 0.2 respectively). The DD in the sporadic FTD group was significantly shorter in females (median DD 7.0 years) in comparison to males (median DD 8.0 years, p = 0.01, Figure 2).ConclusionIn this study we show that females with sporadic FTD have a shorter disease duration than males whereas in genetic FTD the disease duration does not differ between sex. These findings suggest the existence of sex‐related differences in the disease course of sporadic FTD. We urge the need for international epidemiological FTD studies to further explore the role of sex in both genetic and sporadic FTD.

Clinical usefulness of cerebrospinal fluid biomarkers in Alzheimer's disease.

Alzheimer's disease (AD) is a complex disease that shares clinical features with other dementias. It is important to establish a specific and reliable diagnosis. Nowadays, AD diagnosis is based on cerebrospinal fluid (CSF) biomarkers. However, the corresponding cut-offs differ amongst studies. This study aims to evaluate the CSF biomarkers in the AD differential diagnosis. Clinical relevant biomarkers (amyloid β42 (Aβ42), t-Tau, p-Tau, amyloid β40 (Aβ40), neurofilament light chain (NfL)) were determined in CSF samples from participants classified as AD (n=124) and non-AD (n=148) patients from the Neurology Unit. They were included and evaluated consecutively (August 2018-October 2020). The clinical utility of these biomarkers was evaluated by AUC-ROC curves and the corresponding cut-off points were defined. The results showed satisfactory accuracy (AUC-ROC 0.91 for Aβ42, 0.890 for t-Tau and 0.933 for p-Tau); whilst Aβ40 and NfL did not show good discriminatory capacity (AUC-ROC 0.557 and 0.738, respectively). The ratios Aβ42/Aβ40 and t-Tau/Aβ42 improved the diagnosis indices of each individual biomarker, with AUC-ROC of 0.980 and 0.971, respectively. Also, elevated levels of NfL were found in the frontotemporal dementia group compared with the other participant groups. The ratio Aβ42/Aβ40 showed the highest discriminating capacity between AD and non-AD patients and might be useful in clinical practice. Regarding NfL, it is not a specific biomarker for AD; however, it might be helpful for the differential diagnosis of frontotemporal dementia. Nevertheless, further analysis in an external cohort is required in order to validate these results.